Hm, let's see: Do I want to wear out the flash memory in an $800 phone, or get a $150 dash cam?
This comment applies to Android phones that wouldn't let this thing write to a micro-SD card, of course.
One problem is that virtually all dash cams use the same sensor that kind of sucks. You're usually not able to make out people's license plates.
My dashcam was priced like a new iPhone but the recording quality is superb, licence plates of a car 10m away is clearly readable.
Do tell!
you can buy comma.ai hardware, its base use is "dashcam"
you can, at your discretion, load self-driving software (openpilot), which can take over driving for you, in addition to maintaining dashcam footage
they have a subscription that will store footage in the cloud too, iirc